Boost Your Blood to Boost Performance

As a mountain bike racer, I’m pretty familiar with the sight of my blood. But barring blood donations—both accidental and intentional—I’d never thought a whole lot about what is in my O+ life-sustaining fluid until recently. What I learned surprised me.

This past spring, I had the opportunity to ride the Tour of California route in its entirety with GU Energy Labs. While we weren’t going to be “racing” per se, we also weren’t lollygagging or riding recreationally. The goal was to see how our bodies responded to the stress of training leading into the Tour; the stress of riding the Tour as hard as we could; and how we recovered afterward. To that end, GU paired with the health analytics company InsideTracker to do a series of blood draws in the weeks leading up to and then after the Tour. The company scanned our blood for 30 different biomarkers important for energy and metabolism, muscle and bone health, inflammation, strength, endurance, and general health.

My initial readings were okay, but nothing worth crowing about. To be honest, there was considerable room for improvement. In a nutshell, between trying to finish a huge writing project on top of my regular writing gigs, training 15 hours a week, and managing daily life, I was burning through precious resources without replacing them. My body was going into emergency mode, eating into its own tissues to get what it needed, and my blood was becoming a bit of a mess. The first round of readings looked like this:

Glucose: Borderline high. This has been the case for the past few years. Routine bloodwork reveals my fasting glucose hovers above 100, when it should be below, especially for my exercise level and body composition.Total cholesterol: High. Like glucose, this one is always a little higher than I’d like, sitting between 213 and 240 (239 is the cutoff for high). But since my HDL (the good stuff) is generally between 110 and 130, I don’t sweat it too much.Vitamin D: On the low side.Vitamin D is essential for building bones and maintaining muscle.Vitamin B12: A little low. This is an important one for cyclists because B12 helps to make red blood cells and turn the protein you eat into pedal pushing muscles.Iron: My iron levels were good—for now—but unless I got my B12 in line, I learned that I could be on my way to anemia; not good for an endurance athlete.Cortisol: My stress hormone levels were borderline high and just a few ticks from being fully in the red. Since cortisol is responsible for providing energy, maintaining blood glucose, and helping with carbohydrate, protein, and fat metabolism, it can mess up the other biomarkers when it’s high. Which, judging from those numbers above, appears to be the case.

What was going on? For one thing, my self-defined "healthy diet" needed work.

I’ve been tinkering with it for years, trying to find the sweet spot where my energy is high, weight is stable, and performance and recovery are good. For me, that’s meant dialing down the carbs, increasing the fat, and holding the protein stable. Most recently, I was relying more on fruits and vegetables than grains to get most of my carbs off the bike, and just made sure I was fueling myself steadily on the bike.

I evidently needed to dial it back in the other direction. My veggies were filling me up before I’d get sufficient carbs. As my go-to nutrition guru Stacy Sims, PhD, of Stanford explained, “The high cholesterol, LDL, concomitant with high glucose reflects a rebound from your low-carb diet.” Essentially, going very low-carb can cause your body to react in a way that actually increases your fasting blood sugar, especially if you’re stressing it with training and not giving it the carbs needed to recover. Sims stressed that I needed a minimum of 150 grams (600 calories) of carbs a day as a baseline and additional carbs to fuel and recover from all my riding. I’m honestly not a gram counter, but I made a point afterword of including a serving of starch, like a scoop of rice, pasta, or some sweet potato, in all my meals.

Being stressed only amplified things. Juggling too many bowling pins led to that extra mid-morning espresso to rev up and that extra glass of wine to wind down. My outlet was my training, but it was also adding to the stress—especially since, as mentioned above, I wasn’t fueling properly. The result? Cortisol goes up, blood sugar rises, lipids get out of whack, and levels of essential nutrients dip.

Ashley Reaver, RD, the lead nutrition scientist at InsideTracker, echoed Sims’ recommendation for adding more high-fiber, nutrient-rich carbs like oats, beans, and wheat germ into my diet, as well as watching the caffeine and alcohol. She also recommended Vitamin D and magnesium supplements, which help with blood sugar control, energy production, and muscle contraction.

What’s most interesting to me is that I would never have guessed any of these markers were out of whack. I felt great in training and was getting good results in my races. I always feel pretty good even when, on paper, my body's struggling—which sounds like a good problem to have, but really means I could be silently and slowly doing serious damage to my overall health without seeing the signs.

Equipped with valuable data and expert recommendations, I felt determined to bring those markers into ranges that fuel not only performance and recovery, but also general health. After just three weeks of following my plan, I had another blood draw, and saw improvements across the board. What first caught my eye was that my glucose fell below 100 for the first time in many years. My LDL cholesterol also went down; my vitamin D and B12 went up; and most importantly, my cortisol dropped into the “optimal” zone.

Did I feel any different? I’d be lying if I said I felt radically better on the bike. But I did notice some measurable improvements in my well-being. My weight stabilized instead of bobbing up and down. I didn’t have the late-afternoon and evening sugar cravings that use to see me wander toward the pantry, searching for a jar of nut butter and some honey, spoon in hand. I also slept more soundly, and good sleep in itself leads to good recovery, which helps improve stress, blood sugar, and everything else.

Power in the Blood
We fortified our blood even further during the Tour itself. Magdalena Boulet—vice president of innovation, research, and development at GU Energy Labs, as well as an accomplished ultra endurance athlete and exercise physiologist—told us to pop 500mg pills of branched-chain amino acids (BCAAs, like leucine, valine, and isoleucine) before rolling out, and again when we finished. BCAAs, which account for 33 percent of muscle tissue, stimulate muscular protein growth and reduce muscle breakdown. They also help reduce mental fatigue, which can be significant when you’re pushing an average of 100 miles or more day after day.

Immediately after finishing each day, we’d drink GU’s Recovery Drink Mix, which contains dextrose (a simple sugar to restock our glycogen stores) as well as 1000mg of leucine and high doses of the amino acids arginine and glutamine, to further boost recovery and support immunity. (Note: You can get simple sugars and amino acids through other recovery drinks; the trip was through GU, so that’s what we drank.) Finally, before bed, we’d mix drinks of milk or almond milk with an extra scoop of casein, a whey protein that absorbs slowly and so gradually work its way into our bloodstream, providing a steady dose of muscle-mending amino acids while we slept.

This increased influx of BCAAs worked, and I think is particularly important for me as a woman: Female hormones make us more susceptible to being catabolic (eating our own muscle tissue—which we already have less of than men) after hard bouts of physical exertion. I felt reasonably fresh each morning and got stronger as the week progressed. That’s not to say I didn’t have any bad moments; I most certainly did, but they were less frequent than I'd expected.

Not surprisingly, my cortisol, blood sugar, and some other markers shot up again in my post-ToC blood draw. But a red-eye home across the country and wading into a sea of deadlines will do that to you—which leads me to my biggest take-home lesson from this whole escapade.

I had originally been a bit apprehensive about all this in-depth analysis. I wasn’t sure I wanted all this information. I mean, if I felt good, I must not have anything to worry about, right? Also, knowing how my lifestyle and diet directly impact my blood—and hence my health—gives me more reason to want to maintain them well. I’ve seen firsthand that it doesn’t take much to mess it up, but on the flipside, I’m able to improve it in a short amount of time by feeding myself a little better. That’s knowledge I can use both on and off the bike for the rest of my life.

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